Utilization of a very small anomalous diffraction signal provided by sulfur atoms of the cysteine and methionine residues, intrinsically present in all proteins can be succssfully used to solve crystal structures of proteins. This approach, in part pioneered by us, is currently gaining increasoing popularity and may become a routine technique in the practice of macromolecular crystallography. The diffraction data to extremely high resolution of 0.65 angstrom were measured using synchrotron radiation, and the refined model reveals the unprecedented structgural details of the molecule of lysozyme. The observed very fine features in this structure will serve to improve the stereochemical libraries used for routine refinement of protein crystal structures at lower resolution. We participated in several collaborative structural projects on various biologically important proteins, such as the studies of the bacterial and human enzymes active in the mitochondrial mRNA degradosome.